Door-spring



UNITED STATES PATENT OFFICE.

ZENAS COBB, OF CHICAGO, ILLINOIS.

`DOOR-SPRING.

SPECIFICATION forming part of Letters Patent No. 240,811, dated May 3, 1881.

Application tiled November 17, 1880. (Model.)

To all whom it may concern:

Be it known that I, ZENAS COBB, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new anduseful Improvements in Door-Springs; and-I hereby declare the following to be a full, clear, and exact description thereof, reference bein g had to the accompanying drawings, of which- Figure 1 is a horizontal section of a door and casing provided with my device 5 Fig. 2, a longitudinal section of the device itself, and Fig. 3 a detail view.

My present invention relates to certain improvements upon the door-spring for which Letters Patentof the United States No. 201,500 were granted to me March 19, 1878.

In my said former invention an arm or lever, attachedby a bar to the j amb, operated to compress a helical spring encircling a rod set into a suitable bed-plate screwed to the door, all as in my present device 5 but the construction was such that after the door had been opened to an angle of ninety degrees the tendency of the spring was to push it still farther open instead of to close it. My object is to change this feature, so that the spring shall operate to shut the door until it has passed an angle of about one hundred and eighty degrees; and, furthermore, to provide means whereby the device may be made to exert a greater or less force with the same spring, and thus be readily adapted to doors of different weights.

To these ends my invention consists, iirst, in connecting the short arm of the operatinglever, by means ot' a stirrup, to the end ofthe rod which passes through the spring, and, secondly, in providing the long arm of the said operating-lever with an extension at a right angle, or nearly so, said extension having a series of holes for the adjustment to different positions ofthe bar which connects it to the jamb, all as hereinafter more fully set forth.

In the drawings, Ais the bed-plate, adapted to be screwed to the door B, as represented in Fig. 1. This bed-plate is provided with two goose-necks, o, at one end, and with two more,

o', considerably shorter than the iirst, at the opposite end. The inner end or edge of each goose-neck is notched or recessed, as shown at u.

C isalever provided with1 trunnions t, which rest in the notches u of the goose-necks c, to form a fulorum, and I) is the spring which surrounds a rod, E, having a head, F, with ex-` tension s, notched at its extremity. The spring is retained between the head F of the rod and a ring, G, through which the rod passes freely, and which is provided with trunnions t', which bear in the recesses u upon the inner edges of goose-necks o.

In myformer Letters Patent, abovereferred to, the short arm of the lever C was pivoted immediately to the head F of the rod. The obvious effect of that construction is to cause the spring to operate to shut the door only until the latter has passed the position indicated by the dotted lines in Fig. 1, when, the shot arm having crossed the dead-center, the ten ency of the springjEdse-dtmtheother direction, and thus throw the door against the wall. While such an action is sometimes desirable, it is rather a disadvantage in a majority of cases. I accordingly now connect the short arm ofthe lever C to the head ofthe rod by means of a link or stirrup, H, pivoted to each. The obvious effect of this construction is to cause the spring to force the said short arm in the same direction until the door has been opened to au angle of one hundred and eighty degrees, or nearly so, and thus to opdoor. For convenience of adjustment, the-stir- `rup may be pivoted to the head F of the rod by means of a pin, q, near the end of the stirrup, adapted to fit in the notch at the end of the extension s, as shown.

The second feature of my improvement lies in providing the long arm ofthe lever C with an extension, I, at a right angle, or nearly so, with the said arm, and having a series of holes, p, through it, into any one ot' which the bar K may be hooked.

If it is desired to have the spring exert the greatest possible force, the bar K is hooked into the hole over the end of the lever, corresponding to the construction shown in mysaid former Letters Patent. If the least force is re- 2. In combination with the bed-plate A,

spring D, and rod E, having the head F, the 15 lever C, pivoted to the said bed-plate, and connected tothe head of the rod E, and provided with the extension I, having' holes p, said extension projecting from the outer end of the lever C at a right angle, or nearly so, with said 2o lever, substantially as described.

ZENAS COBB.

In presence of- GEo. N. MOORE, FRANKLIN P. SIMoNs. 

